Seen from the front, you get a better view of the riffle plate or I guess you could call it a box. The black bar in the middle rotates. When it is down it holds the riffle box. When you turn it up, you can pull the riffle box with the heavies at the top of the riffles out and dump the material in a bucket to later pan. Waste material piles up near the wheels on this model. There are a number of variations on the market. There are also directions on the Internet for how to build your own. This wooden model is fairly heavy. Most people want one made of aluminum so it isn’t so heavy to carry.